The present invention relates to an electronic connector, and in particular, to a single in-line memory module (SIMM) socket for receiving a circuit board, module, or edge card therein. More particularly, the present invention relates to a terminal designed for use in a socket so that the socket has a higher density and an increased output compared to conventional sockets.
SIMM sockets that are used to couple two printed circuit boards together are well known. One such SIMM socket is illustrated in U.S. Pat. No. 5,013,264 which is assigned to the same assignee as the present invention. The electronic industry constantly demands smaller and smaller components in a continuing effort to miniaturize. The present invention is an improvement over existing SIMM sockets in that the contacts or terminals are configured to permit twice as many input/output (I/O) leads in the same amount of space as a conventional SIMM socket. The connector of the present invention takes up about 65% less space than conventional connectors and includes its own built-in card guides. The terminals are designed so that the functional range of performance is not compromised due to the reduced size.
According to one aspect of the present invention, the terminal includes a non-movable generally L-shaped base and a swan neck contact coupled to one end of the base. The swan neck contact includes a tapered functional portion or spring section and is designed so that the mechanical stresses imparted on the contact during insertion of an edge card are distributed throughout the entire length of the swan neck to maximize the range of performance and mechanical stability.
Another aspect of the present invention is the provision of a "split dimple" formed on a base portion of the terminal to provide a front-to-back alignment of the terminal inside terminal-receiving cavities formed in the socket housing. The split dimple also provides the terminal with a strong retention to the plastic body of the connector housing. During the molding of plastic components to form the plastic socket housing, warping of the plastic often occurs due to shrinkage of the plastic during the cooling process. This warpage can be seen as a frown in the part. Advantageously, the split dimple of the present invention provides an opposing front-to-back force which, when the connector housing is fully loaded with terminals, eliminates the frown. The split dimple also centers the terminals within the terminal-receiving cavities in the housing.
Yet another aspect of the present invention is that the socket housing is formed to include integral stabilizing beams which are flexible to grip and hold a circuit board, module, or edge card in a stable vertical position. These stabilizing beams permit a reduction in the height of the SIMM socket. This stabilizing beam feature by itself is well known in the art. However, the electrically independent terminals of the present invention, when used in a SIMM socket which includes the stabilizing beams, provides significant advantages in reducing the size of the socket while increasing the number of I/O leads.
Conventional SIMM sockets are designed such that conductive pads on opposite sides of a module or edge card are electrically interconnected. Conventional SIMM sockets incorporate contacts with opposed beams comprising a redundant interface for engaging conductive pads on opposite sides of the module or edge card. In other words, the opposed beams in conventional SIMM sockets are coupled electrically. Redundancy in conventional SIMM sockets provides assurance of noninteruptive electrical connection.
In the present invention, contacts on opposite sides of the edge card received in the socket are electrically isolated or independent from each other. By incorporating electrically independent contacts into a SIMM socket, the present invention permits twice as many I/O leads in the same amount of space compared to a conventional SIMM socket and doubles the number of pads per module. The terminals of the present invention are discrete instead of "dual" opposed or redundant as in conventional SIMM sockets.
Additional objects, features, and advantages of the invention will be become apparent to those skilled in the art upon consideration of the following detailed description of a preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived.